Meanings of become a cesspool in English

Thus the ocean has become a cesspool.

But for all the valuable information social media can provide in these moments, it can also become a cesspool of misreported leads.

Business methods and software patents have become a cesspool of attempts to control what many observers feel to be routine and obvious procedures.

This should be particularly so in Dublin which has become a cesspool of provincial penetration and corruption with never-ending tribunals of inquiries costing millions.